import numpy as np

data1 = np.array([[1, 2, 3], [4, 5, 6]])
print(data1.dtype.name)

data2 = data1.astype(np.float64)
print(data2.dtype)

data3 = np.array([1.2, 1.3, 1.4, 3.3])
data4 = data3.astype(np.int64)
print(data4.dtype)

data5 = np.array(["1", "2", "3", '4'])
data6 = data5.astype(np.int64)
print(data6)
print(data6.dtype)